This invention relates to an adjustable threshold assembly of the general type disclosed in U.S. Pat. No. 5,010,690 which issued to the assignee of the present invention. In this assembly, a sliding water seal is provided between the outer exposed portion of the sill member and the vertically adjustable rail member which receives a flexible sweep seal mounted on the bottom edge portion of a swinging door. The above patent discloses the use of an extruded semi-rigid sealing element having a series of vertically spaced flexible fins for slidably engaging the opposing vertical surface of the adjustable rail member. Other forms of extruded sealing members which are mounted on the sill members and slidably engage adjustable rail members, are disclosed in U.S. Pat. Nos. 3,967,412 and 5,001,865.
It has been found highly desirable to provide a threshold assembly with an adjustable rail member for obtaining an effective seal between the threshold assembly and the bottom edge portion of a swinging door it its closed position. However, a sliding water seal between the adjustable rail member and the sill member always provides the possibility of a leak path developing between the sealing member and the rail member, for example, by a small stick or pebble which is deposited on the sealing member by the shoe of a person crossing the threshold. If water leaks past the sliding sealing member, it is possible for the water to penetrate and damage the underlying wood base of the threshold assembly or the wood floor which supports the threshold assembly.